The present invention relates to folding panels made of water-proof thin fabric or films, which are adapted to form moveable partition walls or doors which can be folded in an accordion-shape or in a zigzag manner.
Such foldable panels, typically of the vertically folding type, are utilized for selectively insulating premises and closing or dimming apertures inside or outside industrial buildings. The panels have to be designed to withstand medium winds and to be tight so as to prevent important heat losses.
In a known arrangement, the flexible and foldable panel is formed of different sections, each made of two water-proof non-transparent pieces of fabric of identical dimensions, which are mounted one parallel to the other by means of screws or rivets on several parallel aluminum sections having a length in the transversal direction of the panel greater than the transversal width of the pieces of fabric and arranged at regular intervals all over the height of the panel. The protruding ends of said sections support rollers which are guidingly supported on two parallel tracks arranged vertically on both lateral sides of the aperture to be closed or partitioned. By means of a cable and winch mechanism the lowermost section can be displaced up or down and, when raised, drives the other sections upwardly as the panel is opened, said latter being progressively folded in a zigzag manner in the upper part of the aperture.
A disadvantage of such a panel is that it shows poor insulating properties by reason of the aluminum sections interposed between the elementary panel sections made of two joined fabric pieces, whereby there is no convenient closure of the vertical lateral spaces between two aluminum sections which results in the existence of air circulation paths at the level of the vertical lateral parts of the panel, thereby preventing convenient saving of heating energy. On the other hand, such panels present mounting problems for assembling the fabric pieces and the aluminum sections by means of the screws or rivets, with the appended drawbacks of increased manufacturing costs. Further, utilization of non-transparent fabric pieces does not insure convenient safety in industrial plants and hinders saving of light energy.
In order to obviate some of said drawbacks, foldable panels have also been proposed which comprise a single non-transparent cloth or web, eventually provided with one or several transversally extending windows out of flexible transparent plastic material bonded on openings formed within the non-transparent cloth. Onto said cloth are welded several cloth bands of reduced width having a length corresponding to the transversal width of the panel, said bands being mounted at regular spaces over the height of the panel. The thus secured bands are shaped to form transversally extending sheaths into which are inserted metallic tubes, the opposite ends of which protrude from the sheaths so as to be each guided within parallel C-shaped sections arranged vertically on both sides of the aperture to be closed. When the foldable panel is unfolded to close said aperture, the metallic tubes are thus suspended at regular intervals. In order to make the thus closed aperture free, the panel is folded in a zigzag manner by raising the lowermost tube by means of straps which are slidingly guided in rings mounted on the intermediary tubes. When the lowermost tube is raised, it drives successively the different intermediary tubes upwardly so as to group same in the upper part of the aperture, the foldable panel being thus completely folded in accordion.
With such panels, the thin cloth shows reduced insulating properties, whereby causing great heat losses in the heated buildings and preventing substantial energy saving. Additionally, the straps for raising the panel are slidingly received within the rings arranged on the intermediary upper tube and friction between the rings and the straps cause rapidly damages to said latter. On the other hand, the cloth which has been cut to permit protrusion of the rings connected to the tubes show, at the level of said cut portions, zones of reduced mechanical strength.
Accordingly, it is an object of the present invention to provide a simple and efficient foldable panel, typically a vertically foldable and extendable panel, which obviates said drawbacks of the prior art techniques in permitting a substantial reduction of the heat losses, whereby allowing to save heating energy, the panel being at least partially transparent, whereby offering, due to the convenient visibility through the panel, an improved safety in industrial utilizations wherein displacements of persons or vehicles or loads are numerous and fast. According to another object of the invention, the thus provided panel permits to save electrical energy which may be required for lighting the premises during the day.